[api] Deprecate unused Map/Set FromArray factory methods

These were added when I thought they would be useful in Blink, but as
it turned out they were not. They could likely be deleted immediately,
but to play it safe I'll go through the usual deprecation process.

Review URL: https://codereview.chromium.org/1236263004

Cr-Commit-Position: refs/heads/master@{#29690}

include/v8.h

@@ -3015,8 +3015,9 @@ class V8_EXPORT Map : public Object {
    * in the same manner as the array returned from AsArray().
    * Guaranteed to be side-effect free if the array contains no holes.
    */
-  static V8_WARN_UNUSED_RESULT MaybeLocal<Map> FromArray(Local<Context> context,
-                                                         Local<Array> array);
+  static V8_WARN_UNUSED_RESULT V8_DEPRECATED(
+      "Use mutation methods instead",
+      MaybeLocal<Map> FromArray(Local<Context> context, Local<Array> array));
 
   V8_INLINE static Map* Cast(Value* obj);
 
@@ -3054,8 +3055,9 @@ class V8_EXPORT Set : public Object {
    * Creates a new Set containing the items in array.
    * Guaranteed to be side-effect free if the array contains no holes.
    */
-  static V8_WARN_UNUSED_RESULT MaybeLocal<Set> FromArray(Local<Context> context,
-                                                         Local<Array> array);
+  static V8_WARN_UNUSED_RESULT V8_DEPRECATED(
+      "Use mutation methods instead",
+      MaybeLocal<Set> FromArray(Local<Context> context, Local<Array> array));
 
   V8_INLINE static Set* Cast(Value* obj);
 

test/cctest/test-api.cc

@@ -21735,7 +21735,6 @@ TEST(Map) {
   CHECK_EQ(3, contents->Get(2).As<v8::Int32>()->Value());
   CHECK_EQ(4, contents->Get(3).As<v8::Int32>()->Value());
 
-  map = v8::Map::FromArray(env.local(), contents).ToLocalChecked();
   CHECK_EQ(2U, map->Size());
 
   CHECK(map->Has(env.local(), v8::Integer::New(isolate, 1)).FromJust());
@@ -21769,16 +21768,6 @@ TEST(Map) {
 }
 
 
-TEST(MapFromArrayOddLength) {
-  v8::Isolate* isolate = CcTest::isolate();
-  v8::HandleScope handle_scope(isolate);
-  LocalContext env;
-  // Odd lengths result in a null MaybeLocal.
-  Local<v8::Array> contents = v8::Array::New(isolate, 41);
-  CHECK(v8::Map::FromArray(env.local(), contents).IsEmpty());
-}
-
-
 TEST(Set) {
   v8::Isolate* isolate = CcTest::isolate();
   v8::HandleScope handle_scope(isolate);
@@ -21800,7 +21789,6 @@ TEST(Set) {
   CHECK_EQ(1, keys->Get(0).As<v8::Int32>()->Value());
   CHECK_EQ(2, keys->Get(1).As<v8::Int32>()->Value());
 
-  set = v8::Set::FromArray(env.local(), keys).ToLocalChecked();
   CHECK_EQ(2U, set->Size());
 
   CHECK(set->Has(env.local(), v8::Integer::New(isolate, 1)).FromJust());